Extractives content in cooperage oak wood during natural seasoning and toasting; influence of tree species,geographic location,and single-tree effects

The chemical composition of cooperage oak wood is highly variable, depending upon the tree species (Quercus robur L. versus Quercus petraea Liebl.), its geographic location, and the single-tree effect. In the process of cask-making, natural seasoning and toasting contribute strongly to the modification of the oak wood chemical composition and therefore influence wine cooperaging. HPLC and GC quantification of ellagitannins and volatile compounds such as whiskey-lactones, eugenol, and vanillin over a sample set of 61 pedunculate oaks and 72 sessile oaks originating from six different forests showed that natural drying leads to a decrease of the ellagitannins and total extractives content level and a quasi constant level of the volatile compounds. Toasting (medium type) drastically enhanced the loss of ellagitannins and the gain in volatile compounds. Statistical treatment showed that the species effect remained significant throughout the process of drying and toasting, but not the provenance. The poor correlation with ring width of extractives levels measured on fresh timber remained unchanged as did the single-tree effect, with high variability found for all chemical parameters. These results provide further evidence that cooperage oak selection should not be based solely on the wood grain or the provenance but rather on a species-provenance combination.     

Method for co-purification of equine neutrophil elastase and myeloperoxidase from a limited blood volume

Neutrophil myeloperoxidase (MPO) and elastase can be released in severe inflammatory diseases and cause tissue injuries. Equine enzymes have already been individually purified from large blood quantities. We describe the isolation of both enzymes from a same limited blood volume. Both MPO and elastase were extracted by crushing PMN isolated by centrifugation on a percoll-gradient from a 460 ml blood collection. MPO and elastase were separated by an ionic exchange chromatography phase and further purified by gel filtration chromatography on Superdex 200 and 75, respectively. Enzymes were identified in the collected fractions by specific enzymatic assays. The final purity was verified by electrophoresis. Specific activity was improved to 19.92 and 34.3× for elastase (final yield: 340 μg) and MPO (final yield: 130 μg), respectively, during the procedure. Results show the possibility of isolating both enzymes from the same blood sample with a sufficient yield and purity for future studies on their implication and interaction during inflammatory diseases.     

Cranial vena caval thrombosis secondary to invasive mediastinal lymphosarcoma in a cat

A 12-year-old female cat was diagnosed with a cranial vena caval thrombosis in association with a mediastinal lymphosarcoma. The cause of the cranial vena caval thrombosis was thought to be invasion of the venous wall by neoplastic lymphoid cells. Clinical signs of cranial vena caval thrombosis, such as swelling and oedema of the submandibular area, the ventral part of the neck and the forelimbs, were related to a space-occupying mediastinal lymphosarcoma, which also induced respiratory distress and cyanosis. Non-selective angiocardiography demonstrated the occlusion of the cranial vena cava and abnormal venous collateral vessels feeding the heart which are accepted as the venographic hallmark of clinically overt cranial vena caval syndrome. At postmortem examination, an intracaval thrombus, 5 cm in length, was seen extending from the costocervical vein to the sulcus terminalis of the right atrium.     

Ermittlung von Zink-Ertragsgrenzwerten für Hafer und Weizen

Evalution of critical Zn contents of oats and wheat The minimum Zn content of oats and wheat required for high grain yields is determined in water culture experiments. Zn contents of above ground parts of plants at the beginning of tillering are closely correlated with grain yields (r² about 80 %) and thus suitable to characterize the Zn status. At least 25 ppm Zn in the dry matter of plants at the beginning of tillering are necessary for highest yields. This value can also be derived from 290 Schleswig-Holstein field samples. No influence of increasing contents of other nutrient elements on the critical Zn content can be found.     

Plant cell membrane as a marker for light-dependent and light-independent herbicide mechanisms of action

Plant cells possess a number of membrane bound organelles that play important roles in compartmentalizing a large number of biochemical pathways and physiological functions that have potentially harmful intermediates or by-products. The plasma membrane is particularly important as it holds the entire cellular structure whole and is at the interface between the cell and its environment. Consequently, breaches in the integrity of the lipid bilayer, often via reactive oxygen species (ROS)-induced stress membrane peroxidation, result in uncontrolled electrolyte leakage and in cell death. A simple 3-step bioassay was developed to identify compounds that cause electrolyte leakage and to differentiate light-dependent mechanisms of action from those that work in darkness. Herbicides representative of all known modes of action (as well as several natural phytotoxins) were selected to survey their effects on membrane integrity of cucumber cotyledon discs. The most active compounds were those that are known to generate ROS such as the electron diverters and uncouplers (paraquat and dinoterb) and those that either were photodynamic (cercosporin) or caused the accumulation of photodynamic products (acifluorfen-methyl and sulfentrazone). Other active compounds targeted lipids (diclofop-methyl, triclosan and pelargonic acid) or formed pores in the plasma membrane (syringomycin). Herbicides that inhibit amino acid, protein, nucleotide, cell wall or microtubule synthesis did not have any effect. Therefore, it was concluded that the plant plasma membrane is a good biomarker to help identify certain herbicide modes of action and their dependence on light for bioactivity.     

Intraspecific Variation in Phytophthora citrophthora from Citrus Trees in Eastern Corsica

Isolates of Phytophthora pathogenic to citrus crops on Eastern Corsica and associated with gummosis were identified by PCR-RFLP of internal transcribed spacers (ITS) sequences and characterized by the random amplified microsatellites (RAMS) technique. A sample of 114 isolates collected from diseased trunks and fruits, and from soil, were overwhelmingly Phytophthora citrophthora. Further analysis indicated that the P. citrophthora population was not homogeneous in citrus groves. There were two groups, with a few (4%) atypical isolates in two marginal groups. The major groups have been re-examined in the light of mating behaviour, RFLPs of mitochondrial DNA and sequence comparisons of ITS regions of rDNA. They were found distinct with all these criteria and perhaps constitute distinct taxa. The results indicate that important modifications occurred in the population structure of P. citrophthora over time in Corsican groves. These changes may have impact on the recent outbreaks of gummosis.     

United States Department of Agriculture-Agricultural Research Service research on natural products for pest management

Recent research of the Agricultural Research Service of USDA on the use of natural products to manage pests is summarized. Studies of the use of both phytochemicals and diatomaceous earth to manage insect pests are discussed. Chemically characterized compounds, such as a saponin from pepper (Capsicum frutescens L), benzaldehyde, chitosan and 2-deoxy-D-glucose are being studied as natural fungicides. Resin glycosides for pathogen resistance in sweet potato and residues of semi-tropical leguminous plants for nematode control are also under investigation. Bioassay-guided isolation of compounds with potential use as herbicides or herbicide leads is underway at several locations. New natural phytotoxin molecular target sites (asparagine synthetase and fructose-1,6-bisphosphate aldolase) have been discovered. Weed control in sweet potato and rice by allelopathy is under investigation. Molecular approaches to enhance allelopathy in sorghum are also being undertaken. The genes for polyketide synthases involved in production of pesticidal polyketide compounds in fungi are found to provide clues for pesticide discovery. Gene expression profiles in response to fungicides and herbicides are being generated as tools to understand more fully the mode of action and to rapidly determine the molecular target site of new, natural fungicides and herbicides.